Consider the chemical equation for the production of water: 2 H2+O2>2 H2O. If 100 grams of oxygen gas are used, what would the percent yield be if 75 g of H2O was produced?

66.7%

Explanation:

The balanced equation for the reaction is given below:

2H2 + O2 - > 2H2O

Next, we shall determine the mass of O2 that reacted and the mass of H2O produced from the balanced equation. This is illustrated below:

Molar mass of O2 = 16x2 = 32g/mol

Mass of O2 from the balanced equation = 1 x 32 = 32g

Molar mass of H2O = (2x1) + 16 = 18g/mol

Mass of H2O from the balanced equation = 2 x 18 = 36g

Summary:

From the balanced equation above,

32g of O2 reacted to produce 36g of H2O.

Next, we shall determine the theoretical yield of H2O. This can be obtained as follow:

From the balanced equation above,

32g of O2 reacted to produce 36g of H2O.

Therefore, 100g of O2 will react to produce = (100 x 36) / 32 = 112.5g of H2O.

Therefore, the theoretical yield of H2O is 112.5g

Finally, we shall determine the percentage yield of H2O as follow:

Actual yield = 75g

Theoretical yield = 112.5g

Percentage yield = ?

Percentage yield = Actual yield / Theoretical yield x 100

Percentage yield = 75/112.5 x 100

Percentage yield = 66.7%

Therefore, the percentage yield of H2O is 66.7%